Belt buckle



July 25, 1967 K. PIGIEL 3,332,120

BELT BUCKLE Filed Sept. 16, 1964 ,4H/vw' 4. March A TTOR NE Y United States Patent O.

3,332,120 BELT BUCKLE Kazimierz Pigiel, 376 Fairview Ave., Bridgeport, Conn. 06611 Filed Sept. 16, 1964, Ser. No. 396,877 3 Claims. (Cl. 24-171) The invention relates to buckles for use with belts, straps and the like.

Buckles with friction bars sliding in Icam grooves to cause a belt or strap to bind and thus to hold at any point have long been known. Such bars have relied solely on the direct binding force to hold the belt and have therefore been able to apply only a limited binding force.

The principal object of the invention is to provide an improved friction holding device for a buckle whereby the ends of the strap or belt may be secured at any point and in such a manner as to force the holding device t grip the belt tightly as soon as any pressure is exerted to slide the free end of the belt out of the buckle and to increase the gripping force as more effort is exerted to pull the belt out of the buckle.

Another object is to increase the binding pressure on a belt in a friction-operated buckle beyond the direct binding force available from a friction bar.

The buckle of the present invention has a -front plate with side flanges extending from two of its edges to form a shallow, U-shaped channel into which the free end of the belt slides. The flanges have cam grooves that slant so that they are closer to the plate at the end of the channel through which the free end of the belt enters than they are near the center of the plate. A pivot pin slides in the cam grooves and pivotally supports a friction locking member. The latter is free to pivot through a limited `angle when the pin is opposite the central portion of the plate but this freedom is reduced as the pin slides along the grooves toward the plate. The locking member extends perpendicular to the pin and not only frictionally engages the back surface of the belt to press the belt firmly against the back of the plate but, by virtue of the moment arm of the locking member, increases the pressure on the belt in direct response to any force attempting to withdraw the free end without first loosening the locking member.

Other objects of the present invention will become apparent from a reading of the `following description taken in conjunction with the accompanying drawings wherein:

FIG. l is a view of the back of the buckle and the arrangement of its components;

FIG. 2 is a cross-sectional View of the buckle, taken along the line 2-2 of FIG. 1 with the frictional locking member unlocked; and

FIG.` 3 is a cross-sectional view of the buckle in locked position.

Referring to the drawing, the buckle comprises a longitudinally curved front plate 10, formed with spaced parallel anges 11 and 12 at its edges.

A pivot pin 13 extends through cam grooves in the flanges 11 and 12. At least one outer end of the pin 13 is threaded and a round nut 14 is attached thereto. The other end of the pin 13 may also be threaded or it may have a fixed head 16. The pin 13 extends through a tube 17 to which is attached a locking member 18 that extends laterally on both sides of the tube 17. A clamp 19 is pivotally attached to the flanges 11 and 12 to hold one end of a belt 21.

FIG. 2 shows the buckle of FIG. 1 in cross section. As may be seen, the flange 12 has a cam groove 22 which slants toward the front plate and toward the edge 23 thereof past which :the free end 24 of the belt enters the buckle. In the`drawing, the free end 24 of the belt has 3,332,120 Patented July 25, 196'7 ICC been inserted far enough to extend completely through the buckle and out of sight beyond a belt loop 25.

The locking member 18 comprises a back plate 26 which is attached to the tube 17 by brazing or welding or the like. The back plate 26 has two end flanges 27 and 28 that enclose a friction pad 29, and two straps 20 go across the edges of the pad 29 to hold the pad in place, only one of these straps 20 being shown in FIGURE 2. The friction surface of the pad 29 has a number of ridges 31 on it, perpendicular to the length of the free end 24 of the belt to increase the friction between the pad 29 and the belt.

FIG. 2 also shows the locking number 18 in an alternative position in broken lines to illustrate the fact that the locking member is free to pivot to a limited extent about the pin 13 by means of the tube 17 Welded thereto pivoting to some extent about the pin 13. The pin therefore becomes in effect an axle about which the locking member rotates. The pivotal lmovement of the locking member 18 makes it easier for the locking member to catch the free end 24 of the belt 21. Thus, in the position indicated in broken lines, the back edge of the locking member is shown touching the end 24 of the belt. As a result, any attempt to withdraw the belt will drag the entire locking member along, causing the pin 13 to slide in the cam groove 22 and the aligned groove (not shown) in the flange 11.

As the pin 13 slides along the grooves, it Will be obvious that the freedom of the locking member to pivot back and forth becomes more and more restricted until finally the locking member reaches the position shown in FIG. 3 in which it is drawn up snugly against the back of the free end 24 of the belt, pressing the belt against the back of the plate 10. In that position, any attempt to withdraw the free end of the belt by pulling it longitudinally through the buckle will be prevented by the frictional engagement between the ridges 31 of the pad 29 and the belt 24.

Because of the large area provided by the laterally extending friction pad 29, the frictional engagement between the belt and the pad will be much greater than has been possible heretofore in buckles in which the locking member was only a single bar. Moreover, because of the fact that the locking member 18 is pivotally mounted, any attempt to withdraw the free end of the belt will cause the ridges 31a to dig in even harder due to the moment arm between these ridges and the axis of pivoting which will greatly magnify the holding force applied to the free end of the belt.

In spite of the additional restraining force achieved by the laterally extending holding member 18, the buckle can be as easily released as prior buckles merely by sliding the pin 13 manually lalong the cam grooves 22 while at the same time applying a slight pressure to force the free end 24 of the belt to the right by a very small distance.

While this invention has been described in terms of a specific embodiment, it will be understood that modifications may be made therein without departing from the true scope of the invention, as determined by the following claims.

What is claimed is:

1. A buckle comprising a front plate having an entrance edge, and having two side flanges extending from said plate to form with said plate a shallow U-shaped channel; a pair of aligned cam grooves in said flanges, said grooves being slanted so that they are closer to said plate nearer said entrance edge than they are farther away from said entrance edge; a pin extending between and riding in said grooves; and a locking member comprising a back plate pivotally supported near its center, in

relation to said front plate by said pin as an axle, said locking member having one end extending toward said entrance edge and another end extending in the opposite direction whereby said locking member is able to engage a belt and to clamp the belt against the back of said plate and to pivot to hold said belt more rrnly in place, in response to the application of a force tending to withdraw the belt from said buckle.

2. The buckle of claim 1 in which said locking member comprises, in addition, a pad of friction material held by said back plate to move therewith.

3. The buckle of claim 2 in which said pad of friction material has a plurality of ridges extending across the surface thereof, facing said yfront plate to increase the frictional drag of said pad.

References Cited UNITED STATES PATENTS 110,572 12/1870 Kittleman 24-171 650,785 5/1900 Warner 24-196 1,317,186 9/1919 Wallace 24-171 1,729,479 9/ 1929 Hale 24-73 FOREIGN PATENTS 602,397 12/ 1925 France. 431,340 7/ 1926 Germany.

WILLIAM FELDMAN, Primary Examiner.

E. SIMONSEN, Assistant Examiner. 

1. A BUCKLE COMPRISING A FRONT PLATE HAVING AN ENTRANCE EDGE, AND HAVING TWO SIDE FLANGES EXTENDING FROM SAID PLATE TO FORM WITH SAID PLATE A SHALLOW U-SHAPED CHANNEL; A PAIR OF ALIGNED CAM GROOVES IN SAID FLANGES, SAID GROOVES BEING SLANTED SO THAT THEY ARE CLOSER TO SAID PLATE NEARER SAID ENTRANCE EDGE THAN THEY ARE FARTHER AWAY FROM SAID ENTRANCE EDGE; A PIN EXTENDING BETWEEN AND RIDING IN SAID GROOVES; AND A LOCKING MEMBER COMPRISING A BACK PLATE PIVOTALLY SUPPORTED NEAR ITS CENTER, IN RELATION TO SAID FRONT PLATE BY SAID PIN AS AN AXLE, SAID LOCKING MEMBER HAVING ONE END EXTENDING TOWARD SAID ENTRANCE EDGE AND ANOTHER END EXTENDING IN THE OPPOSITE DIRECTION WHEREBY SAID LOCKING MEMBER IS ABLE TO ENGAGE A BELT AND TO CLAMP THE BELT AGAINST THE BACK OF SAID PLATE AND TO PIVOT TO HOLD SAID BELT MORE FIRMLY IN PLACE, IN RESPONSE TO THE APPLICATION OF A FORCE TENDING TO WITHDRAW THE BELT FROM SAID BUCKLE. 